The present invention relates to a decorative sheet such as table runner, table cloth, bath room curtain, window lining sheet, bag material and the like, and its manufacturing method and manufacturing apparatus.
Conventional, decorative sheets of the above kind are supplied with improved design characteristics by printing patterns on the obverse or reverse side of a synthetic resin sheet or providing an uneven surface by embossing. Also, bottom dye printing and top dye printing using an embossing roll are known. Besides, there is a chemical embossing process for forming uneven patterns on a synthetic resin sheet with a printing ink incorporated with foam suppressing agent such as trimellitic acid so as to suppress foaming of the printing ink-laid surface of the foamed sheet (synthetic resin sheet).
However, the method of using an embossing roll involves problems such that the uneven patterns provided by the embossing roll are shallow in depth and the patterns are liable to be extinguished, and it is hard to obtain a lustrous sheet of porcelain tone. Moreover, there is a problem that the foamed sheet having a foamed part on the surface is weak in strength, and when the foam suppressing agent is used, no porcelain-like luster is obtainable.
In view of the above, the present inventors proposed methods for producing a lustrous sheet on which uneven patterns are precisely formed in Japanese Patent No. 1669906 and Japanese Patent No. 1767264. According to these methods, a long length base sheet coated on one side with a paste form resin is pressed by thrusting the sheet through the space between the metal cylinder provided with a heating device for gelation and a pressing roll and uneven patterns are formed with uneven impressing patterns formed on either side of the cylinder and the pressing roll. However, in recent years demands for a more design-rich gorgeous decorative sheet are increased.